Analysis of 6,276 connectors for rooftop PV systems

November 13, 2025
Source: ASM International

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Scientists from the U.S. Department of Energy’s Sandia National Laboratories have conducted a failure analysis of 6,276 photovoltaic connectors used in rooftop photovoltaic (PV) systems. The connector analysis was presented in the study “Rapid characterization and failure analysis of 6276 rooftop-harvested photovoltaic connectors,” published in Solar Energy.

PV connectors, which link modules in series and connect PV strings in parallel, have increasingly been recognized as a primary contributor to PV system failures and a source of numerous fire incidents. However, publicly available data on the rates and types of connector failures are scarce, primarily due to the proprietary nature of the information and the need for comprehensive analysis.

This study represents the first large-scale investigation of harvested PV connectors, drawing from a dataset of 6276 connectors from residential rooftop solar systems across the United States.

The outcome of this work established a rapid characterization method for large populations of harvested connectors, incorporating visual inspection, resistance measurements, and X-ray imaging. Also, the analysis made possible by Sandia’s rapid-processing method has revealed, for a population of connector models provided by a single rooftop installer, failure statistics and insights for various connector makes and models, installation practices, operating currents, and internal component displacements.

This research identifies common failure modes that could be considered in future connector designs standards, and operations and maintenance practices, to ultimately improve the reliability of this vital component of PV infrastructure.

For more information:

Sandia National Laboratories
https://www.sandia.gov/

“Rapid characterization and failure analysis of 6276 rooftop-harvested photovoltaic connectors” DOI
https://www.sciencedirect.com/science/article/pii/S0038092X25006796?via%3Dihub